Hydrophilic components for a spin-rinse-dryer

ABSTRACT

A spin-rinse-dryer (SRD) includes a substrate support adapted to hold and rotate a substrate, and a source of fluid adapted to supply fluid to the surface of a substrate positioned on the substrate support. The SRD also includes at least one shield positioned to receive fluid displaced from a substrate rotating on the substrate support. The shield includes a substrate-facing surface that has been particle-blasted to cause the substrate-facing surface to have a hydrophilic characteristic.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority from U.S. ProvisionalApplication Serial No. 60/398,997, filed Jul. 26, 2002, which is relatedto commonly-owned co-pending U.S. patent application Ser. No.09/544,660, filed Apr. 6, 2000, and entitled “Spin-Rinse-Dryer”, whichclaims priority from U.S. Provisional Application Serial No. 60/128,257,filed Apr. 8, 1999. All of the above-referenced patent applications arehereby incorporated by reference herein in their entirety.

FIELD OF THE INVENTION

[0002] The present invention is concerned with spin-rinse-dryers usedfor rinsing and drying semiconductor substrates.

BACKGROUND OF THE INVENTION

[0003] It is known to employ a spin-rinse-dryer (SRD), to dry asemiconductor substrate, such as a silicon wafer, after the substratehas been subjected to a rinsing process. Drying by means of an SRD mayprevent streaking, spotting or the deposit of residue on the surface ofthe substrate.

[0004] In the above-referenced co-pending '660 patent application, anSRD is disclosed in which a substrate is supported in a verticalorientation while being rinsed and spin-dried. The SRD disclosed in the'660 patent application includes a system of shields arranged around therotated substrate to direct away from the substrate fluid that has beenspun off the substrate. It is proposed in the '660 patent applicationthat the shields, or at least a substrate facing surface thereof, beformed of a hydrophilic material such as quartz to prevent droplets fromforming and dripping on the semiconductor substrate positionedtherebelow. For the same purpose, the top of the housing of the SRDdisclosed in the '660 patent application is sloped and hydrophilic.

[0005] The present inventors now propose a cost-effective manner ofproviding the shields, the top and/or an upper door of the SRD housingwith suitable hydrophilic surfaces.

SUMMARY OF THE INVENTION

[0006] According to a first aspect of the invention, an SRD includes asubstrate support adapted to hold and rotate a substrate, and a sourceof fluid adapted to supply fluid to the surface of a substratepositioned on the substrate support. The inventive SRD also includes ashield positioned to receive fluid displaced from a substrate rotatingon the substrate support, and comprising a substrate-facing surface thathas been particle-blasted.

[0007] As used herein and in the appended claims, the term“particle-blasted” shall be understood to include one or more ofgrit-blasted, sand-blasted, bead-blasted and the like.

[0008] According to a second aspect of the invention, a vertical SRDincludes a substrate support adapted to hold and rotate a verticallyoriented substrate, and a source of fluid adapted to supply fluid to thesurface of a substrate positioned on the substrate support. Theinventive vertical SRD according to the second aspect of the inventionalso includes either a single shield or a shield system comprising aplurality of vertically and horizontally staggered shields positioned toreceive fluid flung from a substrate rotating on the substrate support.At least one and preferably each of the shields has a substrate-facingsurface that has been particle-blasted.

[0009] According to a third aspect of the invention, a vertical SRDincludes a substrate support adapted to hold and rotate a verticallyoriented substrate and a source of fluid adapted to supply fluid to thesurface of a substrate positioned on the substrate support. Theinventive vertical SRD according to the third aspect of the inventionfurther includes a housing which encloses the substrate support. Thehousing has a top portion that has a slope adapted to cause fluid toflow therealong away from a region above the substrate support. The topportion has a lower surface that has been particle-blasted. In each ofthe above aspects the particle blasted surface may further includesurface features which increase the area of the particle-blasted surfaceand which may also form channels for directing fluid in a desireddirection so as to avoid fluid drops from impacting the substrate.

[0010] According to a fourth aspect of the invention, a method offabricating an SRD shield is provided. The inventive method includesforming a shield adapted to fit in an SRD housing and having a substratefacing surface adapted to receive fluid displaced from a substrate heldand rotated in the housing. The inventive method further includesparticle-blasting the substrate facing surface of the shield and mayinclude forming surface features therein that increase surface area, orforming channels therein for directing fluid in a desired direction soas to avoid fluid drops from impacting the substrate.

[0011] The particle-blasting of a substrate-facing surface or surfacesof a shield or shields for an SRD, as provided for by the presentinvention, may impart a hydrophilic characteristic to thesubstrate-facing surface or surfaces or may increase the hydrophiliccharacteristic of an already hydrophilic surface.

[0012] Other features and advantages of the present invention willbecome more fully apparent from the following detailed description ofthe preferred embodiments, the appended claims and the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013]FIG. 1 is a perspective view of an SRD in which the presentinvention may be applied;

[0014]FIG. 2 is a side cross-sectional view of the SRD of FIG. 1;

[0015]FIG. 3 is a side cross-sectional view of a shield system that ispart of the SRD of FIG. 1 and in which the present invention may beapplied;

[0016]FIG. 4 is a front cross-sectional view of the SRD of FIG. 1;

[0017]FIG. 5 is a partial isometric view of a shield that may beprovided in accordance with a further aspect of the invention; and

[0018]FIG. 6 is a partial cross-sectional view of the shield of FIG. 5;

DETAILED DESCRIPTION

[0019] In a vertical SRD, a system of one or more shields is employed toreceive fluid thrown off by a substrate which is rinsed and spun withinthe SRD. At least part of the substrate-facing surfaces of the shieldshave a particle-blasted finish. Preferably the particle-blasted finishis sufficient so as to exhibit a hydrophilic characteristic or toincrease the hydrophilic characteristic of an already hydrophilicsurface. The hydrophilic characteristic is desirable to deter formationof fluid drops that might fall on the substrate. The particle-blastedfinish may be applied to the inner surface of a sloping top of the SRDwhich may in one aspect include a moveable door.

[0020] Certain aspects of an exemplary SRD will now be described withreference to FIGS. 1-4. Although the SRD of FIGS. 1-4 is adapted forprocessing vertically oriented substrates, it should be noted that theinvention also may be employed in SRD's that process substrates in otherorientations.

[0021] Referring initially to FIG. 1, reference numeral 101 generallyindicates an SRD. The SRD 101 includes a housing 103. The housing 103has a front side 103 a (FIG. 2), a back side 103 b, a top 103 c, a firstside wall 103 d, and a second side wall 103 e. In the example shown, thetop 103 c of the SRD housing 103 slopes down from the first side wall103 d to the second side wall 103 e so that any fluid which collects onthe top 103 c will tend to flow to the lower side of the top 103 c anddown the second side wall 103 e. It will be apparent that the top of theSRD housing may be sloped in other directions so that fluid will flowaway from the region directly above a substrate being processedtherebelow.

[0022] The top 103 c of the SRD housing 103 has an opening 118 sized toallow substrate insertion and extraction. A slidable door 120 may bemounted on a pair of tracks 123 a, 123 b so as to slide back and forthto open and close the opening 118. A bottom wall 103 f of the SRDhousing 103 may slope to a low point 117. A drain 119 may be coupled tothe bottom wall 103 f at the low point 117 to remove rinsing fluid fromthe SRD housing 103.

[0023] Aspects of the internal structure of the SRD 101 will now bedescribed with reference to FIG. 2. In FIG. 2, a substrate 201 is shownsupported within the SRD 101 in a vertical orientation by a pair ofgrippers G which extend from a rotatable flywheel 205. The flywheel 205may be coupled to a motor 207 via an opening in the back side 103 b ofthe SRD housing 103. A pair of rinsing fluid nozzles 208 a and 208 b arecoupled to a source of rinsing fluid (not shown), and are positioned tosupply rinsing fluid to the front and back surfaces of the substrate201, respectively, (e.g., to the centers thereof).

[0024] A shield system comprising a main shield 213, a lower shield 215and a higher shield 217 is employed within the housing 103 to receivefluid thrown from the substrate 201. The shield system is shownseparately in FIG. 3 and is described in additional detail withreference thereto.

[0025]FIG. 3 is a side cross-sectional view of the shield system of theSRD of FIG. 1. In one embodiment, the main shield 213 takes the form ofa slice of a cone which may surround all or part of the perimeter of thesubstrate 201 positioned on the flywheel 205 (FIG. 2, not shown in FIG.3), and may have a downwardly sloped cross section, as shown. Thus, themain shield 213 slants from a larger diameter to a smaller diameter(e.g., closest to the flywheel 205). These diameters preferably areselected such that the substrate-facing surface 300 of the main shield213 has an angle in the range of 5° to 45° (from normal). In oneembodiment of the main shield 213, the angle of the substrate-facingsurface 300 is 18° from normal. In accordance with the invention, atleast a portion of the substrate-facing surface 300 of the main shield213 has a particle-blasted finish so as to have a hydrophiliccharacteristic, such that fluid displaced from the substrate 201 whichstrikes the substrate-facing surface 300 of the main shield 213 flowstherealong deterring droplets from forming and dripping on the substrate201. Details of the treatment of the substrate-facing surface 300 of themain shield 213 will be described below.

[0026] In one embodiment of the invention, the substrate-facing surface300 and an outer surface 302 of the main shield 213 are parallel, suchthat the outer surface 302 and the substrate-facing surface 300 share acommon downward slope. The outer surface 302 of the main shield 213 mayhave raised regions 301 a, 301 b along respective edges thereof toprevent rinsing fluid from running over the respective edge of the outersurface 302 of the main shield 213 and falling onto the substrate 201positioned below an upper portion of the main shield 213.

[0027] During processing of a substrate 201 in the SRD 101, the mainshield 213 is positioned as shown in FIGS. 2 and 3. However, it will beobserved that in the position shown in FIGS. 2 and 3, a portion of themain shield 213 is above the substrate 201, and so obstructs a path bywhich the substrate 201 is inserted through the opening 118 (FIG. 1) forplacement on the flywheel 205. Accordingly, the main shield 213 ismovable from the position shown in FIGS. 2 and 3 to another position(not shown) in which the main shield 213 does not obstruct placement ofthe substrate 201 on the flywheel 205 (or removal of the substrate 201from the flywheel 205). As shown in FIG. 4, the main shield 213 ismovable between the two positions discussed above by virtue of beingmounted to the housing 103 via a pair of pneumatically driven links 401a and 401 b. In particular, the main shield 213 is coupled to the firstside wall 103 d via the pneumatically driven link 401 a, and is coupledto the second side wall 103 e via the pneumatically driven link 401 b.The main shield 213 may move uniformly forward, or the upper portion ofthe main shield 213 may tilt forward or backward, for example.

[0028] Referring again to FIG. 3, the lower shield 215 provided inaccordance with one embodiment of the invention may also take the formof a cone-shaped slice. In the example shown, the lower shield 215surrounds only the upper half of the perimeter of the substrate 201,although other configurations may be employed. The lower shield 215 mayslant from a larger radius to a smaller radius with the larger radiusbeing closer to the main shield 213 and the smaller radius being fartherfrom the main shield 213. These radii may be selected such that thesubstrate-facing surface 304 of the lower shield 215 has an angle in therange of 5 to 45° (and in one embodiment 360) so that rinsing fluidflows therealong away from the substrate 201. The substrate-facingsurface 304 of the lower shield 215 may, like the substrate-facingsurface 300 of the main shield 213, have a particle-blasted finish so asto have a hydrophilic characteristic. An inventive treatment for causingthe substrate-facing surface 304 to have a hydrophilic characteristic isdescribed below.

[0029] The substrate-facing surface 304 and an outer surface 306 of thelower shield 215 may be parallel in one embodiment of the invention. Thelower shield 215 may be coupled to the back side 103 b (FIG. 2) of thehousing 103 via a bracket 303 (FIG. 3).

[0030] Like the main shield 213 and the lower shield 215, the highershield 217 may be described as a cone-shaped slice (e.g., having adownwardly sloped cross section), which, in the example shown, surroundsthe upper quarter of the perimeter of the substrate 201. The highershield 217 slants from a larger radius to a smaller radius which may beclosest to the flywheel 205 (FIG. 2). These radii may be selected suchthat the substrate-facing surface 308 of the higher shield 217 has anangle in the range of 5° to 45°, and in one embodiment 100, so thatrinsing fluid flows therealong toward the main shield 213 (as furtherdescribed below). The substrate-facing surface 308 of the higher shield217 also may have a particle-blasted finish so as to have a hydrophiliccharacteristic.

[0031] It will be observed that the substrate-facing surfaces 300, 304,308 as illustrated in the drawings are concave, and that the highershield 217 may be coupled to the front side 103 a (FIG. 2) of thehousing 103 via a bracket 305 (FIG. 3).

[0032] The main shield 213, the lower shield 215 and the higher shield217 are arranged in a vertically and horizontally staggered manner toreceive fluid displaced from the substrate 201 and the flywheel 205(FIG. 2) as the flywheel 205 rotates with the substrate 201 supportedthereon. The shields 213, 215 and 217 are adapted to carry fluid awayfrom the region above the substrate 201. In one embodiment, the lowerelevation (or small diameter) edge of the higher shield 217 overlaps thehigher elevation (or larger diameter) edge of the main shield 213, andthe lower elevation edge of the main shield 213 overlaps the higherelevation edge of the lower shield 215, as shown. The edges of theadjacent shields may be closely spaced vertically (e.g., 0.3 inches) sothat in the regions above the substrate 201, fluid flows from thesubstrate-facing surface 308 or 300 of the shields 217, 213 respectivelyto the outer surface 302 or 306 of the shields 213, 215 respectively,with minimal splashing. The close vertical spacing of the shields 213,215 and 217 may also facilitate transfer of fluid along the shieldsystem (as further described below with respect to the overall operationof the SRD 101).

[0033] As previously noted, instead of the higher and lower shields 217and 215 extending around only the top portion of the substrate 201,either or both can extend to surround any portion of, or the entireperimeter of the substrate 201. It should also be understood thatinstead of the main shield 213 extending entirely around the perimeterof the substrate 201, the main shield 213 may extend only along an upperportion of the substrate 201.

[0034] An inner surface of the sloping top 103 c (FIG. 1) of the housing103 may have a particle-blasted finish so as to have a hydrophiliccharacteristic that deters droplets from forming on the lower surface ofthe top 103 c and falling therefrom. Likewise, an inner surface of thedoor 120 may be particle-blasted. A process for fabricating a shieldhaving a particle-blasted finish is described below. Initially, a shieldis formed (e.g., via a vacuum forming process) of an easily abraded yetrigid material such as a polycarbonate or the like. The shield is formedso as to have a suitable shape and size for installation in an SRDhousing (e.g., such as one of the shields 213, 215 or 217). Thus, theshield may have a concave surface which is adapted to be asubstrate-facing surface and to receive fluid displaced from a substratethat is held and rotated in the SRD housing.

[0035] Next the concave surface of the shield is particle-blasted sothat the concave surface has a hydrophilic characteristic. As usedherein a surface has a “hydrophilic characteristic” if an aqueous fluid(i.e., a fluid that is primarily comprised of water, such as puredeionized water (DIW) or extremely diluted fluids, for example asurfactant solution comprising over 90% DIW and preferably at least 98%DIW) in contact with the surface tends to form a sheet rather thandiscrete drops or droplets. An exemplary particle-blasting process thatcreates a polycarbonate shield having a hydrophilic characteristic mayinclude grit-blasting using a blasting medium such as silicon carbide100 black carbon, Anisgrade, available as part no. SC100BEX, from USFSurface Preparation. Grit-blasting with this medium may be performed atan air pressure in the range 75 to 80 pounds per square inch, with anozzle distance from the concave surface of approximately six inches. Inone embodiment of the invention, the nozzle is continuously moved duringthe grit-blasting operation to prevent excessive erosion of the concavesurface. The grit-blasting may be applied to all or a part of theconcave surface, and may result in a surface finish, for example, ofabout RA 60-75.

[0036] After the grit-blasting of the concave surface, the shield may becleaned in a conventional manner (e.g., with deionized water).

[0037] As a result of the grit-blasting, the substrate-facing surface ofthe shield will have a hydrophilic characteristic such that a contactangle between fluid on the surface and the surface itself is increased,thereby promoting sheeting of the fluid and preventing formation ofdroplets that might otherwise fall on the substrate.

[0038] Similarly, the inner surface of the top 103 c of the housing 103and/or of the door 120 may be grit-blasted or otherwise particle-blastedso that the inner surface of the top 103 c has a hydrophiliccharacteristic and thereby encourages sheeting and flowing of fluidalong the top 103 c to the second side wall 103 e of the housing 103 andto discourage formation of droplets on the inner surface of the top 103c and/or on the door 120.

[0039] In an alternative embodiment of the invention, surface featuresare formed in at least the substrate facing surface of a shield, or inthe inner surface of the SRD housing's top and/or in the door of thehousing top. The features increase surface area, creating more areaalong which fluid may flow, and thus deterring drop formation (e.g.,surface features may have generally smooth edges and low profiles so asnot to form an obstacle that might deter fluid flow). Preferably thefeatures also are shaped so as to direct or channel fluid from an apexof the featured surface. Such directing or channeling shapes will beboth non-obstructive to fluid flow (e.g., smooth and having lowprofiles) and will extend along a downward slope (e.g., along theshield's sloped cross section, along the shield's circumference, whichin a vertically oriented shield slopes downwardly or along a slope of atop portion or door of an SRD). Preferably at least a portion of ashield that is at a higher elevation than a substrate, or is directlyabove a substrate has the inventive featured configuration describedabove. A non-substrate facing surface of a shield may also include thefeatures described above. Superior results have been achieved byemploying a surface that is both particle-blasted and has the abovedescribed features formed therein.

[0040]FIG. 5 is a partial isometric view of an exemplary main shield 213a provided in accordance with the alternative embodiment of theinvention, and FIG. 6 is a partial cross-sectional view of thealternative main shield 213 a. As best seen in FIG. 6, the alternativemain shield 213 a may have, for example, a rippled configuration (asindicated at 601), such as the sinusoidal configuration shown. Note thatthe exemplary sinusoidal configuration will direct fluid away from theapex of the featured surface. Other configurations such as chevronpatterns, grooves or ribs that similarly extend along a downward slopewill also serve to direct fluid therealong. In addition, thesubstrate-facing surface of the alternative main shield 213 a may beparticle-blasted so as to have a hydrophilic characteristic. Thepresence of the rippled configuration in the alternative main shield 213a increases the surface area of the substrate-facing surface, therebyincreasing the capacity of the substrate-facing surface for flowingfluid away from the substrate 201. As an alternative to the parallelchannels of the sinusoidal rippled configuration shown in FIGS. 5 and 6,the main shield may be provided with other feature configurations (notshown) to aid in flowing of fluid away from the substrate 201 (e.g., achevron pattern which may be arranged to form channels, on an all overpattern of small features, etc.). Although the exemplary featuredsurface is shown on the main shield of a shield system, it will beunderstood that it may be employed on any shield, or on any surfacewhere fluid droplets may otherwise form.

[0041] In operation of the SRD 101 of FIGS. 1-4, the slideable door 120slides along the tracks 123 a, 123 b to an open position wherein theopening 118 is exposed, as shown in FIG. 1. The flywheel 205 ispositioned and configured (e.g., in a manner described in theabove-referenced '660 application) to receive the substrate 201. Asubstrate handler (not shown) lowers the substrate 201 through theopening 118 and transfers the substrate 201 to the flywheel 205. Thesubstrate 201 is secured to the flywheel 205 (for example, as describedin the above-referenced '660 application). Thereafter, the flywheel 205begins to rotate. The flywheel 205 may initially rotate at a relativelyslow speed (e.g., 100 to 500 revolutions per minute (rpm)) while therinsing fluid nozzles 208 a, 208 b supply rinsing fluid to the center ofthe front and back surfaces of the substrate 201. After the substrate201 is sufficiently rinsed, the motor 207 may increase the rotationalspeed of the flywheel 205 (e.g., to approximately 1000 to 2500 rpm) suchthat rinsing fluid is displaced from the substrate 201 via the increasedrotational speed.

[0042] During both the rinsing and drying steps, rinsing fluid may beflung from the substrate 201 to the substrate-facing surfaces 300, 304,308 (FIG. 3) of the shield system. The majority of the fluid is receivedby the main shield 213, but fluid may also land on the lower shield 215,the higher shield 217, and the lower unshielded portions of the housing103 or may condense on the lower surface of the top 103 c of the housing103.

[0043] In one embodiment, the main shield 213 may be angled such thatfluid which impacts the main shield 213 is at least partially reflectedtherefrom toward the front side 103 a of the housing 103 and thereforedoes not collect on the main shield 213. Further, part or all of thesubstrate-facing surfaces 300, 304, 308 of one or more of the shields213, 215 and 217 have been particle blasted in accordance with theinvention so as to have a hydrophilic characteristic, so that fluidwhich is not reflected therefrom travels therealong in a sheet, ratherthan forming droplets which may fall onto the substrate 201. Fluid mayflow along the downwardly sloped cross section of the substrate-facingsurface 308 of the higher shield 217 to the top/non-substrate-facingsurface 302 of the main shield 213.

[0044] Fluid may travel from the non-substrate-facing surface 302 of themain shield 213 to the non-substrate-facing surface 306 of the lowershield 215 and from the non-substrate-facing surface of the lower shield215 to the back side 103 b of the housing 103. The rinsing fluid maythen flow along the back side 103 b of the housing 103 to the bottom 103f of the housing 103 where fluid may be removed by a pump, which is notshown.

[0045] Similarly, fluid may flow from the substrate-facing surface 300of the main shield 213 to the non-substrate-facing surface 306 of thelower shield 215. In one aspect, due to the relatively steep angle ofthe lower shield 215, any fluid that lands on either thesubstrate-facing surface 304 or the non-substrate-facing surface 306 ofthe lower shield 215 flows quickly to the back side 103 b of the housing103. Note that any of the shields 213, 215, 217 may have a featuredsurface that increases surface area and deters drop formation aspreviously described. If the featured surface is adapted to direct fluidflow, the featured surface may, for example, have features that directthe fluid along a downward slope of a substrate facing surface and/oralong a downward slope of a non-substrate facing surface of a shield,such that the fluid flows from the substrate-facing surface of oneshield to the non-substrate facing surface of the next lower shield aspreviously described. A shield that has surface features that directfluid along a downward slope of the shield's cross section is shown inthe partial isometric view of FIG. 6.

[0046] If, however, the surface features are adapted to direct fluidalong the inner or outer circumference of the shield (as shown in FIGS.5 and 6), the fluid may flow circumferentially along the shield ratherthan along the shield's downwardly sloped cross section, and/or may flowboth circumferentially and along the downwardly sloped cross section(e.g., in a diagonal manner, as generally represented by arrow A on FIG.5).

[0047] Any fluid which reaches the top 103 c of the housing 103 willtend to flow therealong, due to the slope of the top 103 c, to thesecond side wall 103 e of the housing 103. In at least one embodiment ofthe invention, the inner surface of the top 103 c of the housing 103and/or the door 120 may have been particle-blasted in accordance withthe invention so as to have a hydrophilic characteristic, to promotesheeting of fluid on the inner surface of the top 103 c and the door120, and to tend to prevent formation of fluid droplets thereon.However, should fluid droplets form on the inner surface of the top 103c of the housing 103 and the door 120, the droplets will fall onto thenon-substrate-facing surfaces of the shield system and traveltherealong, rather than contacting the substrate 201. Either the inneris surface of the top 103 c or the door 120 may have features formedthereon to increase surface area and optionally to direct fluid flow,regardless of whether or not these surfaces are also particle-blasted.

[0048] As the substrate 201 rotates, fluid flows along the surface ofthe substrate 201, rinsing residue therefrom. Drying of the substrate201 may be aided by a heating system and/or a gas flow system, which arenot shown herein, but are disclosed in the above-referenced '660 patentapplication. After the substrate 201 is sufficiently dry, the motor 207slows and then stops the rotation of the flywheel 205. The gripperswhich grip the substrate 201 to the flywheel 205 then release thesubstrate, the door 120 slides open and a substrate handler (not shown)extracts the rinsed and dried substrate 201 from the SRD 101.

[0049] The inventive particle-blasted components may be inexpensive tomanufacture and provide superior fluid shielding.

[0050] The foregoing description discloses only exemplary embodiments ofthe invention; modifications of the above-disclosed apparatus and methodwhich fall within the scope of the invention will be readily apparent tothose of ordinary skill in the art. For instance, the shield system mayinclude one or any number of shields. The shield system may be angled soas to direct fluid to the front side, or to the first or second sidewalls of the SRD housing. The substrate-facing and non-substrate-facingsurfaces of each shield need not be parallel. Neither is it requiredthat the shield or shields of the shield system be cone-shaped, nor thatthe substrate-facing surfaces be shaped as shown. Although the shieldsystem has been disclosed in connection with an SRD in which a singlesubstrate is processed at a given time, it may also be applied in an SRDin which a batch of two or more substrates is processed at once. Also,although the present invention has been illustrated with respect to avertical SRD (i.e., an SRD in which the substrate is spun and rinsed ina vertical orientation), it may be employed to an SRD in which thesubstrate is spun and rinsed in a horizontal orientation or anotherorientation other than vertical.

[0051] The present invention may be applied in SRD's used for rinsingand drying silicon wafers and/or in SRD's used for processing othertypes of substrates.

[0052] The invention has been described in connection with an embodimentin which grit-blasting is employed to cause the substrate-facing surfaceof a shield or shields to have a hydrophilic characteristic. However,other types of particle-blasting, such as sand-blasting orbead-blasting, or the like, may also or alternatively be employed.Moreover, all or a part of the substrate-facing surface of a shield maybe particle-blasted. Accordingly, as used herein and in the appendedclaims, a particle-blasted surface includes a surface of which all or apart has been particle-blasted. The surface may be comprised of ahydrophilic material (e.g., coated with a hydrophilic material, having ahydrophilic material insert, or made of a solid hydrophilic material),and the hydrophilic characteristic may be increased byparticle-blasting.

[0053] As noted above, the present invention may be applied in a shieldsystem for an SRD wherein one, two or more shields are included in theshield system. If two or more shields are included in the shield systemany one or more of the shields may have a substrate-facing surfacehaving a particle-blasted finish. Furthermore, the non-substrate-facingsurface of one or more of the shields may be particle-blasted. Also, theinner surface of the top of the SRD housing and/or the door may or maynot be particle-blasted in accordance with the invention regardless ofwhether or not a shield having a particle-blasted surface finish isemployed.

[0054] Although the mounting brackets 303, 305 (FIG. 3) have beenreferred to separately from their respective shields 215, 217, one orboth of the brackets 303, 305 may be integrally formed with therespective shield 215 or 217.

[0055] Accordingly, while the present invention has been disclosed inconnection with exemplary embodiments thereof, it should be understoodthat other embodiments may fall within the spirit and scope of theinvention, as defined by the following claims.

The invention claimed is:
 1. An SRD, comprising: a substrate supportadapted to hold and rotate a substrate; a source of fluid adapted tosupply fluid to a surface of a substrate positioned on the substratesupport; and a shield positioned to receive fluid displaced from asubstrate rotating on the substrate support, and comprising asubstrate-facing surface at least a portion of which has aparticle-blasted finish.
 2. The SRD of claim 1, wherein theparticle-blasted finish has a hydrophilic characteristic.
 3. The SRD ofclaim 2, wherein the substrate support holds and rotates the substratein a vertical orientation.
 4. The SRD of claim 3, wherein at least partof the shield is at a higher elevation than the substrate support. 5.The SRD of claim 4, wherein at least part of the particle-blasted finishis above the substrate when the substrate is held and rotated by thesubstrate support.
 6. The SRD of claim 4, wherein the shield is movablebetween a first position in which at least part of the shield is abovethe substrate when the substrate is held and rotated by the substratesupport and a second position in which the shield does not obstructplacement of the substrate on the substrate support from a positionabove the substrate support.
 7. The SRD of claim 4, wherein theparticle-blasted finish has a downwardly sloped cross section.
 8. TheSRD of claim 7, wherein a top surface of the shield has a downwardlysloped cross section.
 9. The SRD of claim 1, wherein the shieldcomprises polycarbonate.
 10. The SRD of claim 9, wherein the shield is aunitary piece of molded polycarbonate.
 11. The SRD of claim 9, whereinthe particle-blasted finish is a grit-blasted finish.
 12. The SRD ofclaim 1, wherein the shield is a unitary piece of molded polycarbonate.13. The SRD of claim 4, wherein the substrate-facing surface has surfacefeatures for directing fluid from an apex of the shield.
 14. The SRD ofclaim 4, wherein the substrate-facing surface has a plurality ofchannels configured to direct fluid circumferentially along the shield.15. The SRD of claim 4, wherein the particle-blasted finish has adownwardly sloped cross section and wherein the channels are configuredto direct fluid along the downwardly sloped cross section.
 16. Avertical SRD, comprising: a substrate support adapted to hold and rotatea vertically oriented substrate; a source of fluid adapted to supplyfluid to the surface of a substrate positioned on the substrate support;and a shield system comprising a plurality of vertically andhorizontally staggered shields positioned to receive fluid flung from asubstrate rotating on the substrate support, at least one of the shieldshaving a substrate-facing surface that has a particle-blasted finish.17. The SRD of claim 16, wherein the plurality of shields includes: amain shield wherein the substrate-facing surface is angled from a higherelevation closest to a first side of the substrate to a lower elevationclosest to a second side of the substrate so that the fluid flowstherealong to a lower edge of the main shield; a lower shield positionedat a lower elevation than the main shield, extending from a pointbeneath the main shield to a point beyond the lower edge of the mainshield, and being angled from a higher elevation closest to the loweredge of the main shield, to a lower elevation farthest from the mainshield; and a higher shield positioned at a higher elevation than themain shield, extending from a point above the main shield to a pointbeyond the higher edge of the main shield and being angled from a lowerelevation closest to the higher edge of the main shield, to a higherelevation farthest from the main shield.
 18. The SRD of claim 16,wherein at least a portion of the at least one particle-blasted finishhas a hydrophilic characteristic.
 19. A vertical SRD, comprising: asubstrate support adapted to hold and rotate a vertically orientedsubstrate; a source of fluid adapted to supply fluid to the surface of asubstrate positioned on the substrate support; and a housing whichencloses the substrate support, the housing having a top portion thathas a slope adapted to cause fluid to flow therealong away from a regionabove the substrate support, the top portion having a lower surface thathas a particle-blasted finish.
 20. The SRD of claim 19, wherein at leasta portion of the lower surface of the top portion has a hydrophiliccharacteristic.
 21. A method of fabricating a component of an SRD, themethod comprising: forming a shield adapted to fit in an SRD housing andhaving a concave surface adapted to receive fluid displaced from asubstrate held and rotated in the housing; and particle-blasting theconcave surface of the shield.
 22. The method of claim 21, wherein theparticle-blasting step is performed so as to impart a hydrophiliccharacteristic to the concave surface of the shield.
 23. The method ofclaim 21, wherein the particle-blasting step includes grit-blasting theconcave surface of the shield.
 24. The method of claim 21, wherein theforming step includes molding a polycarbonate material.
 25. A shield forat least partially surrounding a substrate to be spin dried, the shieldcomprising: a concave surface adapted to extend at least partiallyaround a perimeter of a semiconductor substrate and to face toward thesemiconductor substrate, and having a particle-blasted finish thatexhibits a hydrophilic characteristic.
 26. The shield of claim 25wherein the concave surface has a plurality of surface features formedtherein so as to increase surface area.
 27. The shield of claim 26wherein the surface features are further adapted to direct fluid from anapex of the shield, when the shield is vertically oriented.
 28. Theshield of claim 27 wherein the concave surface has a sloped crosssection and the surface features are adapted to direct fluid along thesloped cross section.
 29. The shield of claim 27 wherein the surfacefeatures are adapted to direct fluid circumferentially along the concavesurface.
 30. The shield of claim 27 wherein the surface features have asinusoidal cross section.
 31. A shield for at least partiallysurrounding a substrate to be spin dried, the shield comprising: aconcave surface adapted to extend at least partially around a perimeterof a semiconductor substrate and to face toward the semiconductorsubstrate, and having a plurality of surface features formed therein soas to increase surface area.
 32. The shield of claim 31 wherein thesurface features are further adapted to direct fluid from an apex of theshield, when the shield is vertically oriented.
 33. The shield of claim32 wherein the concave surface has a sloped cross section and thesurface features are adapted to direct fluid along the sloped crosssection.
 34. The shield of claim 32 wherein the surface features areadapted to direct fluid circumferentially along the concave surface. 35.The shield of claim 34 wherein the surface features have a sinusoidalcross section.